Microhabitat Structure Research Articles

Habitat Utilization of Endemic Green Pit Viper (<i>Peltopelor trigonocephalus</i>) in the Wet Zone, Sri Lanka

The endemic arboreal pit viper Peltopelor trigonocephalus is restricted to three climatic zones of Sri Lanka. In this study, the habitat utilization of P. trigonocephalus was investigated by active search and the quadrate method between April 2021 and March 2022. Data on 49 individuals of P. trigonocephalus were collected from riparian, forest, and open habitats. A high encounter rate was recorded in riparian habitats which included areas with thick vegetation. Based on Principal Component Analysis, some habitat variables were key determining factors of microhabitat preference of this species. Ambient temperature, distance to stream, canopy cover and light intensity were significantly affecting the occupied microhabitat structure. Ambushing behavior was more prominent and time-consuming than other behaviors, with 42.59% of recorded sit-and-wait hunting activity. The results of this research indicate that P. trigonocephalus actively selects and utilizes the most suitable macro and microhabitats in wet zones, providing crucial insights for the conservation and management of the species as well as its natural habitat.

Nest site vegetation structure influences nest predators and nesting success of understory birds in a dry evergreen forest in northeastern Thailand

Abstract Nest predation is typically the main cause of nest failure in forest understory birds; thus, identification of primary nest predators is key to understanding nest predation patterns. Furthermore, responses of predators are likely affected by vegetation structure, but predator responses to micro-scale habitat characteristics are largely unknown, especially in tropical forests. We used a long-term study with one of the largest datasets of its kind to investigate the extent to which micro-habitat structure (5-m radius surrounding a nest) can predict the likelihood of predation and by which predator. In a secondary evergreen forest in northeastern Thailand, 2013–2021, we found 1,016 active nests of 13 species and 24-hr video-monitored 500 of them. We recorded 336 predation events from 16 nest predator species. From this and previous studies at our site, we identified the top 4 predator species/species-groups accounting for ~83% of predation events: Macaca leonina (northern pig-tailed macaque, 36% of predation events), cat snakes (Boiga cyanea [green cat snake] and Boiga siamensis [grey cat snake]) (20%), Lycodon cf. davisonii (Blandford’s bridle snake, 18%), and accipiters (A. trivirgatus [Crested Goshawk] and A. badius [Shikra]) (9%). These 4 predator species differed in their responses to vegetation structure likely reflecting differences in foraging behaviors. Macaque and accipiters, both diurnal and visually-oriented, tended to depredate more visible/open nests, but macaques depredated nests surrounded by more trees and short woody stems (<3 m tall) compared to raptors. For snakes, both nocturnal, cat snakes depredated nests with higher numbers of both short woody stems and woody climbers, whereas bridle snakes depredated nests with more trees and fewer climbers. As noted previously, nest predator identity is critical to understanding habitat-predation patterns. Our data suggest that nest site vegetation characteristics influence the likelihood of a given species of predator locating a nest and that even small changes in vegetation structure could significantly alter predation patterns.

Hotspot shelters stimulate frog resistance to chytridiomycosis.

Many threats to biodiversity cannot be eliminated; for example, invasive pathogens may be ubiquitous. Chytridiomycosis is a fungal disease that has spread worldwide, driving at least 90 amphibian species to extinction, and severely affecting hundreds of others1-4. Once the disease spreads to a new environment, it is likely to become a permanent part of that ecosystem. To enable coexistence with chytridiomycosis in the field, we devised an intervention that exploits host defences and pathogen vulnerabilities. Here we show that sunlight-heated artificial refugia attract endangered frogs and enable body temperatures high enough to clear infections, and that having recovered in this way, frogs are subsequently resistant to chytridiomycosis even under cool conditions that are optimal for fungal growth. Our results provide a simple, inexpensive and widely applicable strategy to buffer frogs against chytridiomycosis in nature. The refugia are immediately useful for the endangered species we tested and will have broader utility for amphibian species with similar ecologies. Furthermore, our concept could be applied to other wildlife diseases in which differences in host and pathogen physiologies can be exploited. The refugia are made from cheap and readily available materials and therefore could be rapidly adopted by wildlife managers and the public. In summary, habitat protection alone cannot protect species that are affected by invasive diseases, but simple manipulations to microhabitat structure could spell the difference between the extinction and the persistence of endangered amphibians.

Drought influences habitat associations and abundances of birds in California's Central Valley

AbstractAimAs climate change increases the frequency and severity of droughts in many regions, conservation during drought is becoming a major challenge for ecologists. Droughts are multidimensional climate events whose impacts may be moderated by changes in temperature, water availability or food availability, or some combination of these. Simultaneously, other stressors such as extensive anthropogenic landscape modification may synergize with drought. Useful observational models for guiding conservation decision‐making during drought require multidimensional, dynamic representations to disentangle possible drought impacts, and consequently, they will require large, highly resolved data sets. In this paper, we develop a two‐stage predictive framework for assessing how drought impacts vary with species, habitats and climate pathways.LocationCentral Valley, California, USA.MethodsWe used a two‐stage counterfactual analysis combining predictive linear mixed models and N‐mixture models to characterize the multidimensional impacts of drought on 66 bird species. We analysed counts from the eBird participatory science data set between 2010 and 2019 and produced species‐ and habitat‐specific estimates of the impact of drought on relative abundance.ResultsWe found that while fewer than a quarter (16/66) of species experienced abundance declines during drought, nearly half of all species (27/66) changed their habitat associations during drought. Among species that shifted their habitat associations, the use of natural habitats declined during drought while use of developed habitat and perennial agricultural habitat increased.Main ConclusionsOur findings suggest that birds take advantage of agricultural and developed land with artificial irrigation and heat‐buffering microhabitat structure, such as in orchards or parks, to buffer drought impacts. A working lands approach that promotes biodiversity and mitigates stressors across a human‐induced water gradient will be critical for conserving birds during drought.

Distinct microbial communities under different rock-associated microhabitats in the Qaidam Desert

Hypolithic communities, which occupy highly specialised microhabitats beneath translucent rocks in desert and arid environments, have assembly mechanisms and ecosystem functions are not fully understood. Thus, in this study, we aimed to examine the microbial community structure, assembly, and function of light-accessible (under quartz, calcite, and hypolithic lichen-dominated biocrusts) and light-inaccessible microhabitats (under basalt and adjacent soil) in the Qaidam Desert, China. The results showed that hypolithic communities have different characteristics compared with microbial communities of light-inaccessible microhabitats. Notably, hypolithic bacterial communities were dominated by Cyanobacteria, whereas light-inaccessible microhabitats showed a predominance of Bacteroidetes and Proteobacteria. Although the class Dothideomycetes (phylum: Ascomycota) dominated the fungal communities between the two microhabitat types, Sordariomycetes were more prevalent in light-accessible microhabitats. Network and robustness analyses showed that hypolithic communities were less complex and more resilient than microbial communities in light-inaccessible microhabitats. Our results indicated that deterministic processes, specifically homogeneous selection, govern the establishment of bacterial and fungal communities in light-accessible and light-inaccessible microhabitats. The hypolithic community showed an increased frequency of phylotypes that exhibited increased tolerance to functional stress response pathways. In contrast to light-inaccessible microhabitats, light-accessible microhabitats showed a slight decrease and a notable increase in the prevalence of carbon fixation pathways in prokaryotes and carbon fixation in photosynthetic organisms, respectively. For fungi, light-accessible microhabitats enriched saprotrophic and ectomycorrhizal groups. These results highlight the importance of complex and diverse microhabitats in desert regions, which serve as vital shelters for microbes. Combining future research on interactions between hypolithic communities and environments may enhance our current understanding of their pivotal roles in sustaining desert ecosystems. This knowledge then be applied to design and implement informed conservation efforts to preserve these unique rock-associated microhabitats in desert ecosystems.

Ecomorphology of the Locomotor Apparatus in the Genus Cyrtodactylus (Gekkota, Squamata)

Adaptive radiations garner considerable interest from evolutionary biologists. Lizard radiations diversifying along structural niche space often exhibit distinct changes in body and limb proportions. One prediction is that terrestrial species inhabiting open habitats will have relatively longer hindlimbs, associated with faster running speeds, while scansorial species will have relatively shorter limbs to keep the centre of mass closer to the substratum. Alternatively, terrestrial species in densely vegetated habitats could benefit from relatively shorter limbs to prevent entanglement with more frequently encountered obstacles, whereas scansorial species could benefit from longer limbs promoting greater limb spans and static stability. Cyrtodactylus, an ecologically diverse gekkonid genus, includes numerous specialists with narrow structural niches, but the degree of morphological diversification exhibited by these specialists is largely unknown. We investigated associations between locomotor morphology and structural microhabitat use in Cyrtodactylus to test if either of the opposing predictions can be corroborated for this radiation. We measured body length and relative limb dimensions of 87 species, covering multiple independent transitions among structural microhabitat preferences. Using these data, we reconstructed the phylomorphospace and tested for associations between structural microhabitat niche and limb morphology. We found strong separation between structural niche groups in accordance with the second hypothesis, although overlap is evident among functionally related niches such as those of granite and karst specialists.

Anthropogenic effects of habitat modification on anuran species diversity in a swamp forest area, Kenya

AbstractAnuran species are some of the good environmental indicators of habitat quality and condition in ecosystems. This is due to their amphibious life modes and sensitivity to environmental change caused by rapid expansion of agricultural activities, advancement of forest destruction, climate change and emerging infectious diseases. Understanding their diversity and distribution patterns is crucial for the development and implementation of effective species and habitat conservation strategies. The study aimed at assessing and comparing anuran biodiversity and distribution patterns between a protected (North Nandi Forest Reserve) and a non‐protected area (Kingwal swamp) to provide additional baseline information, both being among the underexplored areas in Kenya. Data were gathered in both dry and wet seasons, between October 2022 and June 2023 by employing standard sampling techniques for anurans(Visual encounter and pitfall traps with a drift fence) to maximise detection. Three habitat types‐ farmland, intermediate land and forest were exploited. A total of 1649 individuals from 21 different species, belonging to nine different genera and nine different families were recorded. Ptychadenidae was the most abundant family from the recorded anurans, while Dicroglossidae, Arthroleptidae, Pyxicephalidae and Ranidae were the least. High biodiversity was observed in the forest habitat (Protected) and least in the farmland (non‐protected). The wet season had high species abundance, diversity and richness compared to the dry season. There was a significant difference (p < 0.05) in diversity between the habitats in wet season, but no significance difference during dry season (p > 0.05) except for forest and farmland (p < 0.05). There was a significant difference in species abundance between seasons (p < 0.05), and between habitats (p < 0.05) in all seasons except for farmland and intermediate (p > 0.05), as well as farmland and forest (p > 0.05) during the wet season. Habitat type and season had no influence (p > 0.05) on species richness. Anuran biodiversity is a function of habitat diversity and season, with the associated differences in microhabitat structure providing diverse niches and ways of exploring resources. The modest sampling indicates that Kingwal Swamp and North Nandi Forest Reserve are rich and support anuran species, and the differences in anuran biodiversity between the 3 habitats demonstrates that conservation efforts continue to be a priority.

Thermal biology of Lanthanotus borneensis (Lanthanotidae) in Sarawak, Borneo

Abstract Lanthanotus borneensis, the Bornean earless monitor, is a monotypic member of the family Lanthanotidae, and restricted to the island of Borneo. Little has been published on its field ecology. This study investigated aspects of its thermal biology through an analysis of surface body temperatures of free ranging individuals against corresponding environmental temperatures, in order to explore aspects of microhabitat utilisation in relation to thermoregulation. A generalised linear mixed model shows significant effect of air and substrate temperatures, but not of water temperature. Further, the fixed effects of substrate temperature (coefficient estimate 0.396; ) versus ambient temperature (0.264; ), is suggestive of thigmothermy as the primary mode of thermoregulation. The species does not appear to utilise specific microhabitat structures to thermoregulate, the results of these observations suggesting that it is a thermoconformer.

Effect of climate change on fossorial species: a case study comparing species of the genus Scincella

Abstract For species that have a fossorial habit or that spend most of their time under leaf litter, correlative models may not be sufficient to model their potential risk in the face of climate change; this is the case for the species examined here. In the present study, we compared three different models (maximum entropy correlative models, mechanistic models based on species thermal tolerance, and habitat cover) applied to three lizards of the genus Scincella (S. gemmingeri, S. lateralis and S. silvicola). Models were proposed for current climate scenario, and for 2050 at three SSPs greenhouse gas concentrations, assessing sites with suitable climate and habitat cover, optimum temperature for species survival, and to selecting the best predictive model. Current and future correlative models indicate areas with little climatic suitability within the thermal range that these lizards can tolerate; however, it was possible to corroborate the presence of populations of S. gemmingeri and S. silvicola in areas that do not have climatic suitability, but do have habitat coverage. These results support the hypothesis that the habitat and microhabitat structures protect these species against possible adverse climatic conditions. It may be that it is also necessary to measure physiological variables (to obtain the thermal range of each species), as well to include both habitat type and habitat structure in spatial analysis.

Identifying the abiotic factors that determine the inland range limits of a mesic-adapted lizard species.

For most species, the factors that determine geographical range limits are unknown. In mesic-adapted species, populations occurring near the edge of the species' distribution provide ideal study systems to investigate what limits distributional ranges. We aimed to identify the abiotic constraints that preclude an east-Australian mesic-adapted lizard (Lampropholis delicata) from occupying arid environments. We performed lizard surveys at sites spanning an elevation/aridity gradient (380-1070 m) and measured the prevalence of habitat features (logs, rocks, leaf litter, bare ground, solar radiation) in addition to hourly temperatures in a variety of microhabitats available to lizards. Species distribution models (SDM) were used to identify the macroclimatic variables limiting the species' distribution. At its inland range limit, L. delicata is associated with mesic high-elevation forests with complex microhabitat structures, which gradually decline in availability toward lower (and more arid) elevations where the species is absent. Moreover, L. delicata is absent from sites with a shallow leaf litter layer, in which daily temperatures exceed the species' thermal preference range, which we determined in a laboratory thermal gradient. In regards to macroclimate, SDM revealed that temperature seasonality is the primary variable predicting the species' distribution, suggesting that L. delicata avoids inland areas owing to their high annual thermal variability. By combining multiple lines of evidence, this research highlights that habitat and microclimate suitability-not solely macroclimate suitability-are important range-limiting factors for mesic ectotherms and should be incorporated in studies addressing range-limiting hypotheses.

The rocks are hotter on the other side of the fence: roadside habitats should inform mitigation design

Maintaining viable populations of large reptiles is often challenging in road fragmented landscapes. While mitigation structures can reduce impacts, few studies have investigated how mitigation success can be affected by roadside habitats. In southeast Ohio, USA, we evaluated mitigation effectiveness for state-endangered timber rattlesnakes (Crotalus horridus) at a new highway in a forested landscape. Road construction at the study site created a wide corridor of open canopy habitats (the right-of-way; ROW) containing roadcuts and stone piles. However, exclusion fencing was constructed along the forest-ROW boundary, leaving the open canopy habitats on the road-side of the fence. Over three years, we monitored 6 rattlesnakes using radiotelemetry and found that rattlesnakes repeatedly crossed the fence to access forest-edge and ROW habitats. Rattlesnakes ostensibly crossed through damaged sections of the fence. The ROW was used most intensively by gravid females (n = 2), with their core home ranges overlapping the ROW by more than 50 percent. Despite the fence crossings, all home ranges were bounded by the highway and no rattlesnake road mortality was observed. Operative temperature models revealed that the ROW provided warmer thermal regimes that were rare or unavailable in the forest. On average, field preferred gestation temperatures (Tb = 29.7°C, SD = 1.8) could be attained or exceeded for more than 5 times as many hours per day in the ROW (7.8 hours) than in the forest (1.4 hours). Habitat selection models indicated gravid females selected warmer thermal habitats that were spatially concentrated in the ROW and edge habitats, while non-gravid snakes avoided the ROW beyond the forest edge. Habitat use within the ROW was mostly limited to rocky microhabitat structures, especially riprap stone piles and subsurface rock crevices on roadcuts, which provided buffered thermal regimes with refugia from extreme temperatures during the day and warmer Te through the night. In forested landscapes, we encourage road planners to consider whether new road corridors are likely to introduce basking sites, and if so, maintain those features on the habitat-side of exclusion fencing, and consider restoring basking sites in the surrounding forest to reduce the potential for ecological trap formation.

Large-scale factors controlling biological communities in the Iberian Peninsula: an insight into global change effects on river ecosystems

The ongoing global environmental change poses a serious threat to rivers. Comprehensive knowledge of how stressors affect biota is critical for supporting effective management and conservation strategies. We evaluated the major gradients influencing spatial variability of freshwater biodiversity in continental Spain using landscape-scale variables representing climate, land use and land cover (LULC), flow regime, geology, topography, and diatom (n = 117), macroinvertebrate (n = 441), and fish (n = 264) communities surveyed in minimally impacted streams. Redundancy analysis identified the environmental factors significantly contributing to community variability, and specific multivariate analyses (RLQ method) were used to assess trait–environment associations. Environmental variables defined the major community change gradients (e.g., mountain–lowland). Siliceous, steep streams with increased precipitation levels favored stalked diatoms, macroinvertebrates with aquatic passive dissemination, and migrating fish. These traits were replaced by adnate diatoms, small macroinvertebrates, and non-migratory fish in lowland streams with warmer climates, calcareous geology, agriculture, and stable flow regimes. Overall, landscape-scale environmental variables better explained fish than diatom and macroinvertebrate community variability, suggesting that these latter communities might be more related to local-scale characteristics (e.g., microhabitat structure, substrate, and water physicochemistry). The upslope environmental gradient of river networks (e.g., slope, temperature, and LULC changes) was paralleled to the observed taxonomy-based and trait-based spatial variability. This result indicates that global change effects on riverine biodiversity could emerge as longitudinal distribution changes within river networks. Implementing management actions focusing simultaneously on water temperature, hydrological regime conservation (e.g., addressing LULC changes), and river continuity might be the best strategy for mitigating global change effects on river biodiversity.

Ecological Considerations When Designing Mitigation Translocations: An Australian Reptile Case Study.

Translocation science has made considerable progress over the last two decades; however, reptile translocations still frequently fail around the world. Major knowledge gaps surround the basic ecology of reptile species, including basic factors such as habitat preference, which have a critical influence on translocation success. The western spiny-tailed skink (Egernia stokesii badia) is used here as a case study to exemplify how empirical research can directly inform on-ground management and future translocation planning. A combination of studies, including LiDAR scanning of microhabitat structures, camera trapping, plasticine replica model experiments and unbounded point count surveys to assess predation risk, and visual and DNA analysis of dietary requirements, were all used to better understand the ecological requirements of E. s. badia. We found that the skinks have specific log pile requirements, both native and non-native predator management requirements, and a largely herbivorous, broad diet, which all influence translocation site selection and management planning. The use of E. s. badia as an Australian case study provides a clear strategic framework for the targeted research of meaningful ecological factors that influence translocation decision-making. Similar approaches applied to other reptile species are likely to fundamentally increase the capacity for effective management, and the likelihood of future successful translocations.

Effect of microhabitat characteristics for predicting habitat suitability for a stalking large carnivore—the Eurasian lynx in middle Europe

AbstractLarge European carnivores are generally considered forest animals. However, there are a number of interacting factors that may have different impact on the availability and suitability of habitat for individual species. Felids, because of their stalking hunting mode, are habitat specialists requiring a heterogeneous environment, making them specifically vulnerable to habitat disturbance. The Eurasian lynx (Lynx lynx), despite protection in many European countries, has a surprisingly limited range. To explain environmental factors that affect its distribution, we undertook habitat selection and habitat suitability analyses at the macrohabitat and microhabitat scales, based on lynx occurrence and environmental data in Poland. Since the species occurs in two populations, one of which inhabits lowland and the other mountainous area, we modelled habitat suitability separately in both areas and then extrapolated it for the whole country scale. The lynx selected forests with medium undergrowth density in the lowlands and highly rugged terrain in the mountain areas—a proxy of stalking cover. Habitat suitability modelling performed at the macrohabitat scale identified around 110 000 km2 of habitat available from which 55 700 km2 was classified as high quality including large tracts of forests in western Poland that are beyond the natural range of the lynx. However, the microhabitat model built by including stalking cover variables, decreased high‐quality habitats to only 33% of the area designated at the macrohabitat scale. This model is largely consistent with the current distribution of lynx in Poland. This suggests that the simplified internal structure of forests (lacking understory cover) may act as a hindrance to increasing the distribution of lynx populations and helps to explain its limited range in the Central European lowlands. This research suggests that the microhabitat structure may play the crucial role in the effective conservation of the Eurasian lynx.

Effects of Anthropogenic Disturbance of Natural Habitats on the Feeding Ecology of Moorish Geckos.

Urbanization and anthropic influences can drastically modify a natural habitat and transform it into an easily recognizable "urban habitat". Human activities can also induce less severe modifications of what apparently might still look like natural habitats. Therefore, these subtle alterations may be hidden but can still cause important negative effects on plant and animals. In contrast, some species seem able to take advantage of these anthropic alterations. Here, we examined the possible effects of the anthropogenic disturbance of an apparent natural habitat on the feeding ecology and body condition of Moorish geckos, Tarentola mauritanica. For this, we compared microhabitat structure, invertebrate availability, the diet composition (estimated from fecal contents), diet selection patterns and body condition of the two populations of geckos inhabiting two contiguous small islands. These islands have similar environmental characteristics, but highly contrasting differences in urbanization and anthropogenic influence. We found that, although the abundance of potential invertebrate prey was similar on both habitats, the diversity of invertebrate prey was lower in the altered habitat. As a consequence, although composition of the diet of geckos was similar on both islands, the diversity of prey and food niche breadth were lower in the altered habitat, and patterns of diet selection changed. However, these inter-habitat differences did not seem to affect the body size and body condition of geckos. We discuss how flexibility in feeding ecology may allow some species to cope with small anthropic disturbances of the habitat.

Influence of microhabitat structure on large‐ and medium‐sized mammals in South African forests

AbstractMicrohabitats play a significant role in the persistence of mammalian species and communities. In South Africa, the forest biome is the smallest. It includes the naturally fragmented Southern Mistbelt Forest group, where little is known about contemporary mammalian assemblage dynamics concerning these forest's microhabitats. We determined the microhabitat characteristics that best explained mammalian species' presence and absence in these forests in the northern Eastern Cape and southern KwaZulu‐Natal provinces. We deployed a minimum of 60 camera traps at any time for 24 h/day to monitor mammalian species' presence/absence. We recorded a habitat foliage profile within a 20 m radius around each camera trap. The species most often photographed were Tragelaphus scriptus and Cercopithecus albogularis labiatus, with the least photographed species being Leptailurus serval and Felis silvestris cafra. All mammalian species detected in our study had a negative association with bare ground. Cercopithecus albogularis labiatus, an arboreal species that requires a dense connecting canopy for movement, showed a positive association with crown closure. Our study highlighted that microhabitat variables: leaf litter, crown closure and grass cover played an important role in the presence and persistence of large and medium‐sized mammalian species that inhabit the Southern Mistbelt Forests, which benefits forest conservation management plans.

Heather (Calluna vulgaris) supports spider diversity of oligotrophic peat bogs

The heterogeneity of microhabitats is an important driver of biodiversity. Therefore, conserving habitat heterogeneity at multiple spatial scales is essential to biodiversity conservation. This study investigates the effect and the conservation value of micromosaic heterogeneity provided by the heather (Calluna vulgaris) patches in an Eastern-European peat bog on the spider communities. We found that the heather patches strongly affect spiders; the species richness and abundance were higher in heather than in open bogs. Heather shrubs form a separate special microhabitat, which differs in structure, microclimate and litter quality, and has a significant positive effect on diversity of spiders. Furthermore, we collected smaller spiders and more web builders in heather sites than in control sites, presumably due to the different microhabitat structures and prey availability. However, habitat type did not affect the vertical microhabitat preference of spiders. The species composition of spider communities differed between the two microhabitat types. We identified seven significant indicator species in heather shrubs, whereas three species were significant indicators of control sites. The species richness and the presence of rare and endangered peat bog specialist spider species in heather patches highlight the high conservation value of peat bogs.

Multi-spatial analysis on cave ecosystems to predict the diversity of subterranean invertebrates

Subterranean habitats around the world can shelter diversified and threatened faunal communities. However, issues related to alterations in the landscape and structure of subterranean habitats still need to be better understood. Therefore, we used a multi-spatial scale analysis of land cover, land use, and cave habitats to predict the diversity of communities of subterranean invertebrates. We hypothesized that changes in land cover promote alterations in both faunal richness and composition and microhabitat diversity and that microhabitat features determined subterranean biodiversity. Sixteen limestone caves were sampled in Brazil at micro, meso, and macro scales using quadrats (1m²), transects (100 meters) as sample units inside caves and buffers with the radius of 100 and 250 meters in the surroundings of the cave entrances. Models performed showed that land cover and land use influenced cave environments, regarding both microhabitats traits and terrestrial invertebrate richness and composition. We also observed a relationship between microhabitat structure and terrestrial invertebrate richness and composition. Our results showed that deforested areas had negative effects on species richness and changed their composition, while natural areas had positive effects on microhabitat diversity. The same effects were observed for both 100 and 250 meters buffers. Invertebrate richness was negatively predicted by deforested areas while positively predicted by natural areas. Richness was also positively predicted by the combination of all microhabitat traits, and dissimilarity of fauna was influenced by microhabitat diversity in mesoscale and microscale by all microhabitat elements. The results highlight the importance of the landscape surrounding the caves to conserve the subterranean habitats and their fauna. Due to the spatial and temporal changes in the global environmental scenario, we argue the urgency of further detailed studies in fragmented landscapes to define minimum areas of protection for cave environments.

Intercropping collard plants with coriander modulates behavioral interactions among aphidophagous predators by altering microhabitat structure

Intercrops increase microhabitat structural complexity and may affect the strength of intraguild predation, facilitating the coexistence of species in aphidophagous guilds that share similar resources. Microhabitat structure may also influence the outcome of intraguild predation among larval stages by influencing the selection of oviposition sites. We investigated how intercrops affect intraguild predation, consumption, and behavioral interactions among various life stages of aphidophagous predators. We examined interactions among conspecific and heterospecific pairs of Cycloneda sanguinea (Coleoptera: Coccinellidae) and Chrysoperla externa (Neuroptera: Chrysopidae) in collards planted in monoculture (simple microhabitat) or intercropped with coriander (complex microhabitat). Heterospecific pairs had reduced impact on their shared prey, especially in monocultures. Chrysoperla externa larvae acted as intraguild predators more often than C. sanguinea larvae and changed the foraging behavior of the intraguild prey. Microhabitat complexity in the intercrop did not extend the period of larval coexistence when intraguild predation was strong. Cycloneda sanguinea avoided laying eggs in the presence of C. externa in the monoculture, and tended to lay more eggs in sheltered locations in the intercrop. Conversely, C. externa laid more eggs in the presence of C. sanguinea, especially in the monoculture. Our findings suggest that the increased microhabitat complexity of the intercrop reduced both the encounter rate between intraguild prey and intraguild predator during larval stages, and the overlap in oviposition site selection by adult females. Our findings highlight the relevance of plant diversity and microhabitat architecture in promoting the coexistence of aphidophagous predators throughout their life cycle, and their potential to increase the efficiency of conservation biological control.

The influence of sugarcane pre‐harvest fire on hantavirus prevalence in Neotropical small mammals

AbstractThe use of pre‐harvest fire in sugarcane fields surprisingly results in an increase in the abundance of Neotropical Sigmodontinae rodents, which might carry hantavirus. By contrast, fire suspension induces a decline in rodents in the first 5 years. The present study aimed to evaluate the effect of sugarcane harvest regimes on hantavirus prevalence in wild rodents. Field collections were carried out on a sugarcane production area in Northeast São Paulo, which is responsible for 30% of the ethanol production in Brazil. A few years after pre‐harvest fire suspension, a high prevalence of hantavirus was found in small rodents at lower population density, but apparently higher population growth rate. Differences in life cycle between the rodents and their predators may explain such density patterns, as small rodents can breed twice or even three times each year, whereas their predators usually breed only once a year. Similarly, the temporal dynamics of the predator–prey relationship suggests that hantavirus prevalence is related to small rodent's population growth and not density. OnlyAkodon montensis,Calomys tener, andNecromys lasiuruscontained immunoglobulin G antibodies against the recombinant nucleoprotein ofAraraquara orthohantavirus, a genotype ofAndes orthohantavirus, with no interspecific variation in seroprevalence among these species. However, males presented higher prevalence rate than females, possibly due to a male‐biased dispersal pattern and a higher frequency of antagonistic interactions. Governance measures to mitigate the role of small wild rodents on the emergence of hantavirus in agricultural landscapes dominated by sugarcane plantations should include the use of wildlife‐friendly management techniques (e.g., to mitigate the mortality of the predators of small rodents), human capacity building concerning wildlife‐related conflicts, and multifunctionality of agricultural landscapes. Future studies should prioritize the possible relationship between microhabitat structure and hantavirus prevalence in small rodents in agricultural landscapes dominated by sugarcane fields.